Child mummy offers revised history of smallpox

A child mummy from the 17th century, found in a crypt underneath a Lithuanian church, was discovered to harbour the oldest known sample of the variola virus that causes smallpox.

This research puts a new perspective on a very important disease.

Professor Edward Holmes

An international team including the University of Sydney have published research suggesting smallpox – a pathogen that caused millions of deaths worldwide – may not be an ancient disease but a much more modern killer that went on to become the first human disease eradicated by vaccination.

The genetic research, published in the journal Current Biology, raises questions about the role smallpox may have played in human history.

The findings also fuel a longstanding debate about when the virus that causes smallpox, variola, first emerged and later evolved in response to inoculation and vaccination.

Co-author Professor Edward Holmes is from the University of Sydney’s School of Life and Environmental Sciences, the Charles Perkins Centre and the Marie Bashir Institute for Infectious Diseases & Biosecurity.

Professor Holmes said his latest research, about smallpox, showed that the evolution of the sampled strains dated from 1650.

However it still was not known when smallpox first appeared in humans or what animal it came from.“We don’t know that because we don’t have any older historical samples to work with,” Professor Holmes said.

“This does put a new perspective on this very important disease – but it’s also showing us that our historical knowledge of viruses is just the tip of the iceberg.”